VARIABLE CONTROL HEAD MODEL 100CV, 120AV

The Variable Volume Control head mounted on a standard Tri-Rotor pump body allows for both automatic and/or manual changes in the flow rate of the pump. The automatic response occurs with changes in the operating pressure of the system, causing a sping-loaded hydraulic control mechanism to adjust internally, the stroke of the pump. By using flow controls, the operator can make manual adjustments to increase or decrease the discharge rate as desired.

MANUAL AND VERNIER FLOW CONTROLS

Two flow controls are available: the Manual Flow Control (MFC) for rough adjustments, or Vernier Flow Control (VFC) which is graduated for fine setting and metering. These enable the operator to vary the discharge rate infinitely from 100% down to zero without stopping the pump or changing speed. The plunger under the control stem and control lever assembly, fix the stroke length, i.e. displacement of the pistons.

TO ADJUST CONTROL SPRING TENSION
(3 STEPS)

STEP 1 - STOP PUMP. Unscrew lettered spring cap and insert spring adjusting wrench as shown. Pull wrench toward "increase" and remove pawl pin. DO NOT LET WRENCH GET AWAY. NOTE alignment of holes between pawl plate and underlying top spring plate. Unwind to release spring tension, counting number of top spring plate holes passing hole originally containing pawl pin.

STEP 2 - To reset, pull wrench in direction of "increase" (note arrows on head shell) until the spring begins to tighten against the control lever assembly. Note first coinciding set of holes. Thereafter, continue turning wrench, DO NOT LET WRENCH GET AWAY, until third top spring plate hole is seen. Insert pawl pin to lock top spring plate in this position. Pump will now develop approximately 35 PSI when running against a closed discharge line.

STEP 3 - For greater pressure, turn wrench to higher hole position. With standard spring, each hole represents 10 PSI, DO NOT EXCEED 5 holes. Heavy duty spring gives approximately 15 PSI per hole, DO NOT EXCEED 7 holes.

CAUTION: Spring adjusting wrench is designed to bend if operator exceeds the allowable tension.

TO REVERSE DIRECTION OF ROTATION
(6 steps)

CAUTION: After reversing rotation variable head no longer automatically reduces discharge rate. A relief valve should be installed in the discharge line. For automatic operation, order a head of opposite rotation from the factory.

STEP (A)- Release spring tension as described above.

STEP (B)- Unbolt control head (1) and remove together with pressure control plate (3) and gaskets as one unit (pictured). Make sure gaskets are not damaged.

STEP (C)- Unbolt shaft housing (2) and remove together with rotor group and gasket as one unit.

THIS LEAVES PUMP IN THREE SECTIONS AS PICTURED.

STEP (D)- Turn body (5) "about face" and switch dowel pins.

STEP (E)- Bolt the three sections back together, making sure the shuttle pin enters the bore of the shuttle.

STEP (F)- Reverse the wiring to run motor in opposite direction.